Association of weight loss and decreased food intake with mortality in the oldest population: People in their 80s versus those aged ≥90 years

Objective

This study investigated the relationship between weight loss (WL), decreased food intake (DFI), and mortality among nursing home residents in their 80s and those aged ≥90 years.

Methods

A retrospective cohort study was conducted with 296 residents aged ≥80 years (138 in their 80s and 158 aged ≥90 years) from five nursing homes in Japan. All had care need levels ≥3 and had been admitted for at least 3 months. Data from electronic care records (2016–2020) were analyzed. WL was categorized with cutoffs at 3 %, 5 %, and 10 %, and DFI was assessed with a 10 % cutoff, measured over 90 days post-admission. Cox proportional hazard models evaluated the associations between WL, DFI, and mortality for both age groups.

Results

For residents aged ≥90 years, WL was significantly associated with mortality at all cutoffs: 3 % WL (hazard ratio [HR] 2.22), 5 % WL (HR 3.22), and 10 % WL (HR 8.86). No significant association was found between WL and mortality in their 80s (3 % WL: HR 1.97; 5 % WL: HR 1.27; 10 % WL: HR 1.86). DFI was significantly associated with increased mortality risk in both age groups.

Conclusions

WL of 3 % or more and DFI of 10 % or more within the first 90 days were linked to higher mortality risk in residents aged ≥90 years. For those in their 80s, only DFI was associated with increased mortality risk. Monitoring WL and DFI is crucial for assessing mortality risk, especially in the oldest residents.